The present invention is directed to a method and to an arrangement for location area management in a cellular mobile radiotelephone network.
One or more radio cells are respectively combined to location areas {referred to below as LA location areas) in cellular mobile radiotelephone networks such as, for example, in the digital mobile radiotelephone network according to the GSM standard (Global System for Mobile Communication). A location area is a region in which a radiotelephone subscriber can move arbitrarily without requiring an updating of the location information that is utilized for defining the location of the radiotelephone subscriber. The size of a location area is defined, for example, by the network operator in order to cover the demands raised by traffic density and flow, population density and subscriber mobility. When a radiotelephone subscriber station leaves the location area, an updating (location update) of the location information is initiated. In location area management, location area identifiers are employed for the identification of the location areas, these being capable of being interpreted in the individual mobile switching centers to which a respective visitor register (visitor location register) is allocated.
The mobile switching center with the appertaining visitor register receives the location information about the respective location area with a signaling procedure that sequences between the radiotelephone subscriber station of the radiotelephone subscriber and the mobile radiotelephone network. The mobile switching center assumes jobs of mobility management such, for example, the transmission of a paging given a call directed to the radiotelephone subscriber, the updating of the location information given a change in location area, handing a call connection over from one radio cell to another radio cell (handler), etc. The LA location areas in the GSM mobile radiotelephone network should, on the one hand, be large so that the information about the location area need be changed as seldom as possible and so that the signaling load in the location area management is kept as low as possible; on the other hand, there is a desire for small areas in order to have to transmit the paging in optimally few radio cells.
A packet data service (GPRS, General Packet Radio Service) can be utilized in the GSM mobile radiotelephone network, whereby one or more data packets are transmitted burst-like between the radiotelephone subscriber station and the mobile radiotelephone network (see, for example, GSM recommendation 03.60, version 0.13.0, Feb. 23, 1996). For utilizing the packet data service, location areas (routing areas) (referenced below as RA location areas) are also defined that are serviced by packet data service nodes (GPRS support nodes) (see, for example, page 28 of the GSM recommendation 03.60). These RA location areas are likewise composed of one or more radio cells that usually exhibit a smaller size than the LA location areas of the GSM mobile radiotelephone network. As warranted, they are also the same size. The location area management in the packet data service ensues with smaller RA location areas in order to implement the transmission of the data packets directly into the radio cell to the radiotelephone subscriber insofar as possible. The higher resolution of the location areas for the packet data service results, given employment of the signaling procedure according to the GSM method, in an increase of the signaling load for each mobile switching center. When, by contrast, a separate signaling procedure (for example, upon involvement of the packet data service network node)is employed only for the packet data service, two separate signaling procedures exist side-by-side for the location area management, this running counter to an efficient utilization of the radio resources in the mobile radiotelephone system.